It is well known to include visually contrasting particles, in powdered or granular laundry detergent compositions. The visually contrasting particles may be included as a cue to the consumer, to indicate the presence of some specific quality or ingredient, or may simply be present to give the product an attractive appearance.
GB 2,358,403B discloses colored lamellar polymeric particles that are cut from a planar film in any desired shape, such as numerals, letters of the alphabet, circles, sun, moon and star shapes. Cutting such shapes from a planar film leaves a high percentage of waste film material for recycling. Such recycling of film material is costly and inefficient.
Other patents, e.g., WO 2009/047124 A1, disclose manufacturing lamellar particles by cutting identical shapes from a film, without waste material between the cut shapes, such that the cut shapes can be tiled. Other patents describe additives in the visually contrasting particles, such as a fluorescent dyes (GB 2,358,404 B) or a perfume (WO 2009/047127 A1).
One of the significant problems with the inclusion of visually contrasting aesthetic particles in laundry detergent compositions is that the particles may not completely solubilize during the wash cycle of an automatic washing machine. Insoluble residue from the contrasting particles can remain on the washed fabrics and create an impression of the fabrics not being clean, or the residue could look like specific soiled areas. One published application that describes this problem is WO 2006/079416, claiming visually contrasting aesthetic particles that leave less than 10 wt % insoluble residues. Materials leaving less than 10 wt. % insoluble residues were gum Arabic, casein, hydroxypropyl methyl cellulose, and sodium carboxymethyl cellulase.
Besides being sufficiently soluble, the composition of the aesthetic particles should allow for manufacturing particles having a number of different sizes, shapes and colors in a variety of designs, such as rings, needles, stars and other shapes that will be evocative in the consumer's mind of the finished product.